Method of saturating paper-board or felt.



ELISHA JESSE CADY, OF CHICAGO, ILLINOIS.

METHOD 0F SATURATING- PAPER-BOARD 0R FELT.

Specification of Letters IPatent.

Patented May sa, raie.

Application led December 7, 1914. Serial No. 875,829.

following is a speciiication, reference beingY had therein to the accompanying drawing. My invention relates to the treatment of paperboard used in the manufacture of 'building paper, artificial shingles and the like, and it consists in the novel method of saturating the same with any suitable .solu.

tion or compound as hereinafter set forthI i of Contact so that the liquid may enter beand pointed out in the claims.

Heretofore it has been customary in .saturating paper-board with liquid solutions or compounds to wind a strip or length of the stock, such as strawboard or paper felt, upon a reel in a liquid bath, the stock passing into the bath as it is wound on the reel and then being left on the reel in the bath.

for different lengths of time` ranging from two to six hours according to the density of the stock to allow the liquid to soak into it,

- as its passage through the liquidy to `the reel does not do more than ,merely coat it. lThisv process is objectionable; when porous stock, such as paper felt, is employed the liquid is taken into the pores of the inner convolutions or windings by capillary attraction or action of the stock of the outer ones and the convolutions are not uniformly saturated as the inner ones are loss affected according as they lie nearer the center of the roll, while the saturation of each convolution isnot uniform as its edges exposed to the liquid will become more thoroughly saturated than its uneXposed body, the treatment requiring two to three hours to affect the inner convolutions; when a denser material, such as straw-looard for example, is used the saturation is not uniform for the same reasons, while the saturation of the inner layers requires an even greater length of time as the capillary action of the denser stock is.

slower.

In saturating paperboard lfor use as building material, especially where it is to be used in places exposed to he'at or the sun, uniform saturation is necessary as otherwise the product will warp, and as such warping destroys its \'alue,`the importance of`eliminating this defect is apparent. By the employment of my 4invention l obviate this defeet, besides materially reducing the cost of manufacture and the length of time required to saturate the stock.

My invention, briefly stated, consists in immersing a roll of paperboard. in a liquid solution or compound, preferably of asphalt, with the convolutions of Pthe stock spaced apart to provide circulating space therebetween to permit the liquid to enter between the convolutions to act directly and continuously on allportions of the stock. I employ paperboard, such as `strawboards, chipboards, paper felts or pulpboards for eX- ample, which is. wound in the form of a roll,

and a suitable spacing means is rolled up in the convolutions of the roll to hold tnem out tween the convolutions and act directly and continuously on all portions of the surface of the stock of each convolution. rihe solution or compound for the bath, such as liquid asphalt, is prepared in any usual way now w'ell known in the art for treating paperboard, and is contained in a suitable tank or vessel in such consistency that 'it will readily enter between the spaced convolutions of the stock in the bath and soak into the stock. lThe spacing means interposed between the convolutions of the stock may be of any suitable construction which will prevent Contact between the succeeding convolutions and permit the solution or compound to enter between them and actlwith substantial uniformity onall portions of the stock, such for example as an open-mesh fabric strip, an apron formed with transversely extending bars, or a strip of woven wire fabric. The essential requisite vof the spacing means is that it shall space the convolutions of the stock apart so that the liquid solution or compound ofthe bath may enter between them and act with substantial uniformity on all portions of the stock, and preferably I use an open-work construction so that the liquid may act directly on both sides of the stock. The strip or length of the stock with the spacing means rolled up in its convolutions is immersed in the solution By my invention the saturation of paper-4 boards of different degrees of density is uniform and is completed in less time than was required by the processes heretofore employed. For example, it fis a fact Well known and recognized by the trade that thick dense paperboards, such as straw boards, can be saturated by the methods in use prior to my invention at a maximum speed or rate of only a foot an hour, usually a foot during each hour and a half, while I have demonstrated by actual practice that by my invention uniform and thorough satn uration of such heavy boards can be made on'the basis of approximately afoot during a space of time varying from a minute to a minute and a half. Furthermore, the old methods required that the solid rolls of stock be immersed in the liquid asphalt of the bath for several hours in order for the capillary action of the stock to enable the liquid to evenly coat its inner convolutions, and as it was necessary to maintainthe bath at a high temperature to keep the asphalt liquefiedsuliiciently to soak into the stock, the result was that the exposure of the, stock to the high heat for such a length of timekilled its fibers,whereas vby my invention this defect in the product is obviated as the stock is so rapidly saturated that its fibers are not damaged. My invention enables me to use these cheaper heavy stocks for making various products, such as asphalt shingles which are now largely used, and to produce such products uniformly and thor oughly impregnated or saturated at a cheap commercial rate.

M v invention may be carried out in a variety of ways. and in order to clearly illustrate the preferred manner of practising;r it,

I represent in the accompanying drawingall the special apparatus necessary thereto, though I do not specifically claim said apparatus, which may be of any ordinary construction.

In' the drawing the figure represents a. sectional view of the tank or vessel containing a liquid solution or compound, prefer' the stock is carried into the bath and'iat its rear a pair of rollen-sr. between which the stock passes from lthe tank. rlhe reeling "C suitably situated in the liquid in such location that they may be freely revolved in both directions `by hand or any suitable "means (not shown). flexible apron or belt D is attached at its ends to these -reels so as to Wind on the one While unwinding from the otherA` and is composed of an openmesh textile or metallic fabric, such for example as is formed by interwoven coiled wires of small loops or turns.

In carrying out Amy invention the apron or belt` is wound upon one ofthe reels as vat C for example with its opposite end connected to the reel B, 'and the en d of the length vor strip of stock E is led into the bath and suitably connected to the apron or placed in the bite of the apron and the bar\ rel of the reel B so that as the reel is revolved the stock or material is wound upon it at the same time that the apron is wound upon it withr the convolutions of the apron interposed between the layers or convolutions of the stock to maintain an open space between the layers or convolutions of, the latter and permit the liquid asphalt to directly attack `the stock on both sides and at all points of its surface. After the reel B is thus illed'the completed roll is allowed to stand until the stock is fully saturated when it may be removed by rerolling the apron or belt upon the reel C, the stock being led off between'the pair of rolls a'. lfVhile vthe reel C is preferably located. in the bath to prevent' the solution from solidifying or drying on it, it may be otherwise located.

I claim 1. The method of saturatng paperstock which consists in'rolling up a roll of stock with the convolutions of the stock spaced apart to provide circulating,r space therebetween and saturating all portions of the stock with substantial uniformity in a bathv stock to provide circulating spaetherebe tween. y

3. The method of satnrating paperstock which consists in rolling up a length of stock in a liquid` asphalt bath and rolling;y up an open-mesh apron in the convolutions of the stock to-provide circulating space therebetween. y 4

In testimony whereofI aflixmy signature in presence of two witnesses- ,y 4

f ELISHA JESSEADY.

Witnesses: y

' Enrru Wrncox,

J. MoRonEnTs. 

